The present invention relates to a power supply including at least two parallel switching supply modules each of which includes a current sensor having a terminal which is connected to an error amplifier included in an output-voltage regulating circuit.
Such a power supply, which permits current sharing between the switching-supply modules, is disclosed in DE-OS 30 12 728. The voltage delivered by each current sensor, which is proportional to the current in the respective switching-supply module, is applied from one terminal to the corresponding terminals of the other switching-supply modules and from the other terminal through a voltage divider, to which a reference voltage is applied, to one input of the error amplifier. The output of the switching-supply module is coupled through another voltage divider to the other input of the error amplifier.
When any of the parallel switching-supply modules fails or is switched off, it cannot deliver a voltage proportional to the current. This falsifies the regulation in the other switching-supply modules.